Artocarpus lakoocha Roxb. and Artocarpus heterophyllus Lam. Flowers: New Sources of Bioactive Compounds

Abstract

Artocarpus heterophyllus Lam. (AH) and Artocarpus lakoocha Roxb. (AL) are two endemic plants that grow on the Asian continent. To date, their applications have been aimed at using their fruit as a food source or for some of their therapeutic virtues. In this study, attention was given to the flowers of AH and AL. Initially, the cytotoxicity of the phytoextracts was assessed, and the content of minerals, phenols, and flavonoids was determined. Furthermore, some antioxidant components were identified by HPLC. Furthermore, the ability of AH and AL extracts to modulate the gene expression of some targets involved in the antioxidant response was studied. The results obtained highlighted the nutritional and antioxidant value of the AH and AL flower extracts. This study will contribute to enhancing the use of AH and AL flowers as potential supplements in human nutrition.

Keywords: Artocarpus heterophyllus Lam.; Artocarpus lakoocha Roxb.; DMPD radical; antimicrobial properties; antioxidant properties.

Figure 1

(A) Artocarpus heterophyllus Lam. flowers; (B) tree of Artocarpus lakoocha Roxb. with flowers; (C) upside view of Artocarpus lakoocha Roxb. flower; (D) cut-out section of Artocarpus lakoocha flower.

Figure 2

(A) HPLC chromatogram of standards identified in Artocarpus lakoocha Roxb. and Artocarpus heterophyllus Lam.: cycloartenone (1), lupeol acetate (2), oxyresveratrol (3), α-amyrin acetate (4), and β-amyrin acetate. (B) HPLC chromatogram of Artocarpus lakoocha flower extracts. (C) HPLC chromatogram of Artocarpus heterophyllus Lam. flower extracts. (D) The chemical structure of the main components.

Figure 3

Effects of flower aqueous extracts of Artocarpus lakoocha Roxb. and Artocarpus heterophyllus Lam. on Caco-2 cell viability. (A) The bars indicate percent cell viability of cells treated with one of the two floral extracts with the indicated concentrations (ranging from 0 to 50 μg/mL) for 48 h and subjected to a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data are representative of three replicates and shown as mean ± standard deviation; *** p < 0.001 vs. Artocarpus lakoocha Roxb. untreated group; ^&&& p < 0.001 vs. Artocarpus heterophyllus Lam. untreated group. (B) Effects on Caco-2 cell cytotoxicity after 48 h treatment with aqueous solution extracts of Artocarpus lakoocha Roxb. and Artocarpus heterophyllus Lam. Only concentrations of 0, 5, 15, 25, 35, and 45 mg/mL are shown in the image.

Figure 4

2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging activity: (A) Artocarpus heterophyllus Lam. flower extracts, (B) Artocarpus lakoocha Roxb. flower extracts. All measurements were performed in triplicate. Data are shown as the mean ± standard deviation, and one-way ANOVA with a Newman–Keuls post-test was used for statistical significance; * p < 0.05 vs. 1 µg/mL ascorbic acid; ^$ p < 0.05 vs. 1 µg/mL methanol extract; ^# p < 0.05 vs. 1 µg/mL water extract.

Figure 5

Ferric-reducing antioxidant power (FRAP) assay: (A) Artocarpus heterophyllus Lam. flower extracts, (B) Artocarpus lakoocha Roxb. flower extracts. All measurements were performed in triplicate. Data are shown as the mean ± standard deviation, and one-way ANOVA with a Newman–Keuls post-test was used for statistical significance; * p < 0.05 vs. 1 µg/mL ascorbic acid; ^$ p < 0.05 vs. 1 µg/mL methanol extract; ^# p < 0.05 vs. 1 µg/mL water extract; ^& p < 0.05 vs. 1 µg/mL ethanol extract.

Figure 6

DMPD (N, N-dimethyl-p-phenylenediamine) radical cation decolorization assay: (A) Artocarpus heterophyllus Lam. flower extracts, (B) Artocarpus lakoocha Roxb. flower extracts. All measurements were performed in triplicate. Data are shown as the mean ± standard deviation, and one-way ANOVA with a Newman–Keuls post-test was used for statistical significance; * p < 0.05 vs. 1 µg/mL ascorbic acid; ^$ p < 0.05 vs. 1 µg/mL methanol extract; ^# p < 0.05 vs. 1 µg/mL water extract.

Figure 7

mRNA expression in Caco-2 cells of heme oxygenase-1 (HO-1) (A and B), nuclear factor (erythroid-derived 2)-like 2 (Nrf2) (C and D), and NAD(P)H quinone reductase (NQO1) (E and F) after treatment with flower extracts of Artocarpus heterophyllus Lam. (left) and Artocarpus lakoocha Roxb. (right), 0–20 µg/mL. Data are expressed as fold changes of the target gene (Nrf2 in A, HO-1 in B, and NQO1 in C) normalized to the internal standard control gene (β-actin). All measurements were performed in triplicate. Data are shown as the mean ± standard deviation, and one-way ANOVA with a Newman–Keuls post-test was used for statistical significance; ** p < 0.005; *** p < 0.0001 vs. 0 µg/mL.